When Ash was 10 (and I think he somehow is still 10?), he left his home in Pallet Town to begin his journey. When he leaves home, we meet his Mom, Delia Ketchum, who we see at various points in the anime after Ash leaves. However, Ash's father is rarely mentioned, and we never meet him. Ash has stated that his dad also began his journey as a Pokemon trainer from a young age, but that is about it.
Does anyone know anything about Ash's dad?
No We don't.
According to Wikia,
From very minor portions of dialogue, it can be assumed that his father started on a journey from Pallet Town much like Ash. Never formally introduced, the identity of his father has always been under heavy speculation. These speculated characters however, have attained no hard evidence that they are in fact related to Ash in any way. In addition to that, during an interview with a storyboard artist for the Anime series, the artist stated that Ash's father is a man who is on his own Pokémon journey as a Trainer's.
Trivia,
In The Spell of the Unown's commentary, the producers announced that more about him will be revealed in season 5, which eventually turned out to be untrue.
In the second Ep of the anime, when ash arrives at Veridian City, Ash's mom tells him that his father took four days to get there while Ash arrived there in one day.
And found this on MAL:
The identity of his father has remained unknown. One reference to him exists in the anime. During a phone conversation between Ash and his mother in the second episode, [...] A line from the play, Pokémon Live!, suggests that Delia, at one time, had a relationship with the leader of Team Rocket, Giovanni when she was a teenager, but in the anime, no evidence of Giovanni being Ash's father has been shown currently.
https://myanimelist.net/character/2473/Satoshi
Just adding to the above.
